[Info-vax] OT: obscure PDP11 OSes (even more dinosaury)

[Bill Gunshannon]

In article <mlp2ba$mlq$1 at dont-email.me>,
	Simon Clubley <clubley at remove_me.eisner.decus.org-Earth.UFP> writes:
> On 2015-06-16, Bill Gunshannon <bill at server3.cs.uofs.edu> wrote:
>> In article <a5da$557f3c62$5ed4324a$14524 at news.ziggo.nl>,
>> 	Dirk Munk <munk at home.nl> writes:
>>> 
>>> So perhaps the PDP-11/74 would have been faster in pure processing 
>>> power, for real world applications the much larger memory footprint a 
>>> VMS application could have was far more important. Anything that can be 
>>> done in memory is much better than having to rely on disk IO.
>>
>> The PDP-11's memory capability was expanded twice, to 18 and then 22 bits.
> 
> So are you saying these later PDP-11s were capable of directly running
> 256K(byte/word) and then 4M(byte/word) binaries without having to use
> overlays or some memory banking arrangement ?

Well, the 4M would be problematic as it wold leave no room for the OS. :-)

No, the last one's I worked on could have 64K data/64K program for user
programs.  But I still think all of this could have been fixed without
abandoning what IMHO was an excellent architecture.

On another side note, Unix was developed on the PDP-11.  I wonder how
much the architecture of the PDP-11 influenced the Unix Paradigm of
multiple connected programs to do a job as opposed to one monolithic
program?  Hindsight is always 20/20.  Looking back now yet another
aspect of Unix makes perfect sense and shows a level of engineering 
that people seem to think Unix doesn't deserve.

bill
 

-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
billg999 at cs.scranton.edu |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>